Ordnance-bore sighting-telescope.



PATENTED JULY 21, 1908. S. OZAPSKI. ORDNANOE BORE SIGHTING TELESCOPE.

APPLICATION FILED OGT.2,1906.

En sTATEs PATENT -OFFlCE.

. SIEGFRIED czAP'sxI, or .TENA, GERMANY, ass tiuon TO THE FIRM or CARL ZEISS, or {TE-NA,

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no. ceases.

Specificationof Letters Patent. I App1i0ation filed October 2, 1906. serial No. 837,180.

Patented my 21, 190's.

To all {sham it may concern:

Be it known that "I, SIEGFRIED OZAPSKI, doctor of philosophy, a citizen of the German Empire, and residing at Oarl-Zeiss strasse,

Jena, inthe, Grand Duchyof Saxe-Weimar, Germany, have invented a new and useful Ordnance-Bore Sighting-Telescope, of which the following, is a s ecification.

The invention re ates to optical appliances to be insertedlinto the bore of guns.

Testing the adjustment of the gun sighting device, telescopic or ordinar that 1s, investigating whether the line 0 aim in its zero positlon be parallel to the axis ofthe bore (that is, whether both be directed upon the same far distant point) has hitherto ordinarily been carried out in the following manner. An ordinary sighting telescope is set in the middle of an insertion piece, which fits into the breech of the gun and this insertion piece is placed in position. In correct adthereupon,

.or whether the telesco justed to ustment of this bore sightin telescope, its line of sight coincides with t e axis of the bore; The bore sighting telescope can then be employed in testing the adjustment of the sighting device. This is done by directing the gun, until a very distant point lies in the line of sight of the bore telescope, and thereafter examining, whether this oint lies also in the line of aim of the gun, w 'enthe sight-, ing device of the latter is set to zero. A bore sighting arrangement as'described must be tested each time before use, b inserting aframe with cross-wires or the ike into the muzzle ofthe gun and focusing the telesco e to see whether its line 'of sig t passes through the middle point of the muzzle eshould bev re-adcauseits line '0 sight to do so. The I zero'position of the line of aim could not otherwise be determined with the necessary high accuracy. With careful construction of the bore sighting telescope the relative p0- Qsition of the line of sight to the telescope casing'will 'notreadily undergo displacement, the relative position of the piece and e gun does not in each renewed adaptation of the appliance coincide sufliciently exactly'with that in which the s1 htin telescope was originally adjusted. his

be understood from the facts, that'the d1- mensions both of the telescope and the insertion piece are comparativey small and a minute angular displacement of the bore telescope represents a coarse error as regards the direction of its line of sight.

Modifying the usual arrangement, so that the specified coincidence takes efiect auto matically with adequate accuracy and needs no longer to be tested each time before use, is

the pur ose of the present invention. With this en in view, the insertion piece is divided into two separate portions, of which one portion is fitted into the muzzle of the gun and only carries an objective-system, whose focal length is ap roximately e of the barre while the ot er portion of the insertion piece occupies the former position in the breech but is only provided with the ocular and the cross wires or other mark for sighting. '-Since in this arrangement thetwo omts, by which the line'of sight is determined, namely the back 'nodal oint of the objective system and the mid e point of the mark for sighting, lie separated by the length of the barrel, the relative position of the line of sight ,tothe barrel can no. longer be perceptibly influenced, in successive adaptations, by

ual to the length the unavoidable small angular diiferences between successive positions of I the two portions of the insertion piece.

In the .annexed drawing: Figure 1 is a longitudinal vertical section through a gun barrel e uipped with a telescopic sighting device and t e improved gun bore sighting arrangement. Fig. 2 is a front view on an enlarged scale of a cross-lined lano-parallel glass plate comprised in the said arrangement.

The ob ective system a is inserted into the muzzle. Its axis coincides with the axis of the bore. The terrestrial ocular system 1), consisting of 'an astronomical ocular b .and an erecting prism b is inserted with its In the focal plane of the objective, between. the astronomical ocplar and the prism syselongated mount into the cartridge chamber.

tem, cross lines are A rovided on a plano-parallel glass plate If, t eir point of intersection lying on the common axis of the bore and the objective in the focal point indicated in Fig. 1 by convergin rays. The telescopic sighting device 0 oft e gun is placed on the top of a curved bar shown as adjusted in' the zero position, in which the line of aim should be parallel to the axis of the bore. To test this, the gun is directed to some far distant point, so 5 that the image of this point coincides with the center of the cross lines 'on plate I). If then in the sighting device 0 the image of the same point does not likewise coincide with the center of the sigh ting mark, such coincidence may and a breech portion, the muzzle ortion car' rying an objective system, the ocal length of which is a proximately e ual to the length of the barrel? and the breec ortion carrying an ocular system with a mar for sighting. 1 5

c SIEGFRIED OZAPSKI.

Witnesses:

PAUL KnfiGER, FRITZ SANDER. 

